If you are already installed Cyanogenmod 7.1 stable or Cyanogenmod 7.2 rc1/rc2/rc3 on your defy you can upgrade it to now stable version, just download Cyanogenmod 7.2 stable from the link mentioned above. After downloading copy this zip file in your memory card root, just reboot your defy in recovery mode and choose recovery- install zip from memory card, choose zip and install.

Your all settings, contacts, apps with settings will recover automatically. If you are on stock froyo and want to install Cyanogenmod 7.2 stable then follow my previous posts regarding this –